Ios 测量水平面上的ARKIT

如何在放置对象之前使用ARKit Scenekit测量水平平面？在放置对象之前，我想先创建一个房间模型。提前谢谢

事先知道房间的大小是件棘手的事

但是，测量任何检测到的平面的大小不是：

每次检测到水平或垂直曲面时（假设已启用），将生成一个ARPLANEACHOR：

当您运行启用了planeDetection选项的world tracking AR会话时，该会话会自动向其锚定列表中添加一个ARPLANEACHOR对象，该对象对应于使用后向摄影机检测到的每个平面ARK。每个平面锚都提供有关曲面的估计位置和形状的信息

这将在以下委托回调中调用：

 func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { }

func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) { }

因此，您可以获得ARPlaneAnchor的宽度，如下所示：

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

        //1. Get The Current ARPlaneAnchor
        guard let anchor = anchor as? ARPlaneAnchor else { return }

        //2. Log The Initial Width & Height
        print("""
            Initial Width = \(anchor.extent.x)
            Initial Height = \(anchor.extent.z)
            """)

 }

但是，此初始解决方案存在一个问题，即通过以下回调更新ARPLANEACHOR（例如，其大小更改）：

 func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) { }

func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) { }

因此，如果您想跟踪

ARPlaneAnchor

的更新大小，您需要考虑这一点

让我们看看如何做到这一点：

首先，我们创建自己的

SCNNode子类

，称为PlaneNode，即使在更新时也会返回平面的大小

请注意，您不需要创建子类来获得相同的结果，尽管为了便于重用，我已经创建了：

    class PlaneNode: SCNNode {

    let DEFAULT_IMAGE: String = "defaultGrid"
    let NAME: String = "PlaneNode"
    var planeGeometry: SCNPlane
    var planeAnchor: ARPlaneAnchor

    var widthInfo: String!
    var heightInfo: String!
    var alignmentInfo: String!

    //---------------
    //MARK: LifeCycle
    //---------------

    /// Inititialization
    ///
    /// - Parameters:
    ///   - anchor: ARPlaneAnchor
    ///   - node: SCNNode
    ///   - node: Bool
    init(anchor: ARPlaneAnchor, node: SCNNode, image: Bool, identifier: Int, opacity: CGFloat = 0.25){

        //1. Create The SCNPlaneGeometry
        self.planeAnchor = anchor
        self.planeGeometry = SCNPlane(width: CGFloat(anchor.extent.x), height: CGFloat(anchor.extent.z))
        let planeNode = SCNNode(geometry: planeGeometry)

        super.init()

        //2. If The Image Bool Is True We Use The Default Image From The Assets Bundle
        let planeMaterial = SCNMaterial()

        if image{

            planeMaterial.diffuse.contents = UIImage(named: DEFAULT_IMAGE)

        }else{

            planeMaterial.diffuse.contents = UIColor.cyan
        }

        //3. Set The Geometries Contents
        self.planeGeometry.materials = [planeMaterial]

        //4. Set The Position Of The PlaneNode
        planeNode.simdPosition = float3(self.planeAnchor.center.x, 0, self.planeAnchor.center.z)

        //5. Rotate It On It's XAxis
        planeNode.eulerAngles.x = -.pi / 2

        //6. Set The Opacity Of The Node
        planeNode.opacity = opacity

        //7. Add The PlaneNode
        node.addChildNode(planeNode)

        //8. Set The Nodes ID
        node.name = "\(NAME) \(identifier)"

    }

    required init?(coder aDecoder: NSCoder) { fatalError("init(coder:) has not been implemented") }


    /// Updates The Size Of The Plane As & When The ARPlaneAnchor Has Been Updated
    ///
    /// - Parameter anchor: ARPlaneAnchor
    func update(_ anchor: ARPlaneAnchor) {

        self.planeAnchor = anchor

        self.planeGeometry.width = CGFloat(anchor.extent.x)
        self.planeGeometry.height = CGFloat(anchor.extent.z)

        self.position = SCNVector3Make(anchor.center.x, 0.01, anchor.center.z)

        returnPlaneInfo()
    }

    //-----------------------
    //MARK: Plane Information
    //-----------------------

    /// Returns The Size Of The ARPlaneAnchor & Its Alignment
    func returnPlaneInfo(){

        let widthOfPlane = self.planeAnchor.extent.x
        let heightOfPlane = self.planeAnchor.extent.z

        var planeAlignment: String!

        switch planeAnchor.alignment {

        case .horizontal:
            planeAlignment = "Horizontal"
        case .vertical:
            planeAlignment = "Vertical"
        }

        #if DEBUG
        print("""
            Width Of Plane =  \(String(format: "%.2fm", widthOfPlane))
            Height Of Plane =  \(String(format: "%.2fm", heightOfPlane))
            Plane Alignment = \(planeAlignment)
            """)
        #endif

        self.widthInfo = String(format: "%.2fm", widthOfPlane)
        self.heightInfo = String(format: "%.2fm", heightOfPlane)
        self.alignmentInfo = planeAlignment
      }

    }

创建子类之后，我们需要在

ViewController

中使用它。您通常会得到多个

ARPlaneAnchor

，但是在本例中，我们假设会有一个

因此，我们将创建一个引用PlaneNode的变量：

var planeNode:PlaneNode?

然后在ARSCNViewDelegate中，我们将创建PlaneNode，如下所示：

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

    //1. Get The Current ARPlaneAnchor
    guard let anchor = anchor as? ARPlaneAnchor else { return }

    //2. Create The PlaneNode
    if planeNode == nil{
        planeNode = PlaneNode(anchor: anchor, node: node, image: true, identifier: 0, opacity: 1)
        node.addChildNode(planeNode!)
        planeNode?.name = String("Detected Plane")
    }

}

然后，您只需跟踪PlaneNode的更新，例如：

func renderer(_ renderer: SCNSceneRenderer, didUpdate node: SCNNode, for anchor: ARAnchor) {

        guard let anchor = anchor as? ARPlaneAnchor, let existingPlane = planeNode else { return }
        existingPlane.update(anchor)
}

如果一切按计划进行，您应该在

控制台日志中看到类似的内容：

平面宽度=0.07m

平面高度=0.15m

平面对齐=可选（“水平”）

---

希望这足以让你开始……

花点时间在谷歌上搜索我做了……但我还没有找到任何帮助来解决我的问题：(